Echoing the above. Well over a year with a BR RS-4, several hundred hours of dangling cameras, sometimes from a tripod ring, sometimes from the battery grip on the 7D or 5DII. I'm in the habit of checking FastenR and the thumbwheel connecting grip to body every few times I put the camera on. On a couple of occasions, I've found one or the other connection point slightly loose (often the grip thumbwheel) - so, it's a really good habit.
I commonly wear a BR strap and another bag. Sometimes, that's a Lowepro Toploader Pro 55 AW or 75 AW cross-slung, sometimes a loaded Lowepro Flipside 400 AW. As stated, BR strap then backpack, with hip belt and chest strap under the BR strap. Works great.
RE looking like a dork - I think the big camera and lens takes care of that. A few pieces of nylon can't make it much worse. :p